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iPhone 4S dropping network and data at random

Hi,

I've been using an iPhone 4 on a Vodafone contract for the past 16 month and just bought an iPhone 4S direct from Apple. It arrived on Friday morning and I got it set up correctly as far as I can tell.

When I first turn it on, it works lovely and exactly as I would expect, able to make calls, send texts and access the internet via the cellular network. However, at what appears to be random, the network will disappear (no bars of signal) stopping me making calls and texts, but still allowing me to access the internet. Sometimes, the Internet goes, but I can still make calls and texts. Other times, everything is gone and I get "No Signal" where it normally says Vodafone UK.

So when trying to fix this problem after it's noticed, I try putting it into Airplane mode and back out. The phone scans for a network and goes back to the same state as before I tried this fix. I have tried resetting network settings, but this doesn't change anything. The only thing that actually fixes it temporarily is turning the phone right off and back on again.

At this stage I assume this is a bug with the software, but I wondered if anyone else is experiencing anything like this? If no one is, I will take it up with Apple, but I don't really want to do that as I love the new phone so much!!

Cheers, Stuart

iMac (late 2009), Mac OS X (10.6.3), 27" i7 Quad-Core, 4GB RAM, 1TB HDD

Posted on Oct 16, 2011 2:53 AM

1,022 replies

Cubybear

Level 1

0 points

Oct 18, 2011 4:41 AM in response to Stuart Mchattie

Same problem here in France with Orange. I received new I phone 4S since last Friday. Phone only works shortly after I reset. Few minutes after unable to receive or send phone call with full bar on signal. Not even 3G!!

After disabling SIM lock, it works just great!!

Oct 20, 2011 8:37 PM in response to Stuart Mchattie

I am having the EXACT same problem, in the USA, with AT&T. My phone shut off, turned on, and now constantly cycles the cell radio off and on.

This 4s is turning out to be a mess.

UPDATE! I did the disable SIM PIN thing, now it's locked me out. great.

4dncn

Level 1

0 points

Oct 21, 2011 9:52 AM in response to Stuart Mchattie

Thanks for suggesting this. I've been ready to take my phone back to Apple as it just never works. i.e I get off the underground after loosing signal and it never gets cellular signal back again. I either have to power cycle the phone or pop out the SIM.

It's looking better so far will update if the fix holds.

(in UK and on O2)

Oct 21, 2011 11:47 AM in response to Stuart Mchattie

hi ! same issue in france with Orange, i will try to disable pin code, thanks

4dncn

Level 1

0 points

Oct 21, 2011 5:29 PM in response to Stuart Mchattie

This has made a difference. Thanks

I was pretty much on F ALL reception. Loads better now thanks. SIM PIN off on 4S improves reception

Oct 23, 2011 2:32 AM in response to Stuart Mchattie

Hello,

To me, the network lost only happened with I was using a GPS app. (Plan, Glympse).

After less than a minute the little arrow on the top right appeared, the network was drop.

(Searching and no network found).

The tip given on this topic worked for me, disabling the sim code and reseting the network settings.

Thank you 🙂

Ceejay28

Level 1

19 points

Oct 24, 2011 2:32 PM in response to Stuart Mchattie

Wish I read this earlier as I had exactly the same problem, but eventually managed to find the fix independently (after much wasted time at work!).

This is a pretty significant bug in iOS don't you think? Is there somewhere to report such things formally to Apple?

Oct 25, 2011 8:11 AM in response to DJ Hollygrove

Thats pretty odd, as you can on the iPhone 4 but not the 4S, I have had the full signal, but cant make calls or send texts untill I reboot, turned off sim pin and will see how it goes.

Oct 25, 2011 1:11 PM in response to killhippie

Thank you for backing me up here. I hate it when people think being abrasive will get them anywhere. Maybe his phone does have the 3G optionl, but in that case it's either not a 4S or it's really badly messed up as it's not supposed to be there on the 4S.

Good luck with the SIM PIN removal. I notified the guy at the Apple store of the problem but I don't think he paid much attention to be honest.

Oct 25, 2011 3:07 PM in response to Stuart Mchattie

I think some variants of the 4S do have that option, its an AT&T thing, my 4S has the settings for the networks APN as its a sim free model. Call Apple and log it as an issue, point them to this page, I am going to do that, T-Mobile in Germany have it appears been issuing this as advice for people with similar issues. Also people in Australia have reported the problem. I am sure Apple know, but more people saying it to them will not hurt.

Oct 26, 2011 11:13 AM in response to Stuart Mchattie

I have the Iphone 4 with OS 5, SIM pin is off?? What now?

Oct 26, 2011 11:14 AM in response to Stuart Mchattie

I have iphone 4 with OS 5, SIM PIN has always been off?? any other suggestions?

Oct 26, 2011 11:19 AM in response to rhysfromcape town

If you have a 4, not a 4S it may not be related, have you set the phone up as new? Or have you reinstalled it to see if this helps? The two phones have different antenna so its hard to say if its iOS5 or not with yours. my Old 4 was sld on and no issue with that has been mentioned. Try resetting network settings, or contact Apple if its in waranty

Oct 26, 2011 11:21 AM in response to killhippie

Thanks will try that! much appreciated

Oct 26, 2011 11:22 AM in response to rhysfromcape town

It's not a hardware issue, it's software. For some reason, iOS is cycling the radio on and off, I'm guessing something mixed up with SIM pin permissions. What I had to do was turn on SIM pin, then off, at which point it demanded the PUK code. I was able to get it online through my ATT account. After I entered that PUK, then went back into settings and turned SIM pin off, I haven't had any problems.

iPhone 4S dropping network and data at random